Stabilized chlorinated cyanuric acid bleaching compositions



United States Patent "ice 3,278,443 STABILIZED CHLORINATED CYANURIC ACID BLEACHJING COMPOSITIONS Samuel Claude Bright and Allan Alsbury, Bebington, England, assignors to Lever Brothers Company, New York, N.Y., a corporation of Maine No Drawing. Filed July 16, 1962, Ser. No. 210,252 Claims priority, application Great Britain, July 24, 1961, 26,775/61 8 Claims. (Cl. 252-95) The present invention relates to bleaching compositions and, in particular, to bleaching compositions based on chlorinated cyanuric acids and to means of stabilising them.

Trichlorocyanuric acid and dichlorocyanuric acid and mixtures of trichlorocyanuric acid and dichlorocyanuric acid, which substances are meant by the term chlorinated cyanuric acid used herein, are Well known bleaching agents which have been incorporated in bleaching compositions of various kinds. In particular, they have been incorporated in scouring bleaching compositions containing, in addition, large amounts of finely-divided abrasive material such as silica or feldspar, together with minor amounts of alkaline or neutral salts, such as sodium carbonate, sodium orthophosphate, pyrophosphate or tripolyphosphate, sodium silicates and sodium sulphate and of wetting or detergent agents, such as sodium alkylbenzene sulphonates. However, the stability of compositions containing these bleaching agents, especially trichlorocyanuric acid, under normal conditions of storage leaves much to be desired, considerable loss of active chlorine taking place in the time which may elapse between their manufacture and sale to the actual user.

It has now been found that such compositions can be stabilised against a loss of active chlorine by the addition to them of certain unsaturated organic compounds.

The invention provides a bleaching composition containing a chlorinated cyanuric acid, as here-inbefore defined, stabilised by a compound of the general formula R.CH:CH.X, where at least one of R and X is an electronreleasing group.

Stabilisation of chlorinated cyanuric acid in accordance with the present invention can be effected in dry particulate compositions which give neutral, acidic or alkaline solutions in Water.

Preferably at least one of the groups R and X is a phenyl group, a substituted phenyl group, a benzyl (C H .CH group or a benzyl group substituted in the aromatic nucleus (Y C H .CH One of the groups R and X may be a hydrogen atom, a methyl group, an hydroxymethyl (HO.CH group or an ester or ether of an hydroxymethyl group. The groups R and X may be joined together to form a cyclic system. Espe' cialiy preferred stabilising compounds of the present invention have the group CH=CH as part of a C sidechain of a benzene ring which is substituted by at least one ether group.

Compounds chosen to stabilise chlorinated cyanuric acids in. accordance with the present invention should not be readily polymerisable. Styrene, beta-methyl styrene, isopropyl styrene and allylbenzene are not suitable for Patented Oct. 11, 1966 the stabilisation of chlorinated cyanuric acids in accordance with the present invention.

Compounds chosen to stabilise chlorinated cyanuric acids in accordance with the present invention should react with hypochlorous acid but should not have a very low vapour pressure nor yet be extremely volatile. Compounds of boiling point at atmospheric pressure outside the range C. to 360 C. are not contemplated as being normally useful within the scope of the present invention, although compounds boiling below 150 C. may be employed where sealed containers or volatility depressants such as mineral oil are employed. Compounds of boiling point at atmospheric pressure within the range 225 C. to 270 C. are especially preferred. 4,4'-dimethoxystilbene, 4,4-'-diaminostilbene and cinnamyl stearate, which boil above 360 C., are not suitable for the stabilisation of chlorinated cyanuric acids in accordance with the present invention.

Compounds suitable for the stabilisation of chlorinated cyanuric acids in accordance with the present invention include cinnamyl alcohol, cinnamyl cinnamate, anethole, stilbene, indene, methyl eugenol and methyl isoeugenol. Safrole, iso-safrole, eugenol and isoeugenol are especially preferred.

The amount of stabilising compound to be used depends upon a number of factors, such as the physical form of the chlorinated cyanuric acid and the nature of the stabilising compound to be used, the nature and amount of the other ingredients of the composition and the conditions under which it may be stored. It is preferred to use a granulated chlorinated cyanuric acid. Appreciable increases in stability may be obtained with as little as 1%, by Weight of the chlorinated cyanuric acid, of stabilising compound according to the invention, while amounts of up to 50% are generally more than adequate to give substantially complete stability for normal compositions and times and conditions of storage. It is preferred to use from 2% to 20% of stabilising compound by weight of the chlorinated cyanuric acid.

In preparing compositions of the invention, care must be taken that the chlorinated cyanuric acid and the stabilising compound are not brought into contact with one another before at least one of them is, and preferably both are, diluted with or adsorbed on some of the other ingredients of the composition. A slight loss of available chlorine is generally found to have taken place during the process of mixing a chlorinated cyanuric acid with the other ingredients of a bleaching composition such as a bleaching scouring powder, and this mixing loss is often increased by the presence of organic compounds added for the purpose of stabilising the chlorinated cyanuric acid on storage. It is a further advantage of many of the compositions of the invention that this mixing loss is found to be relatively small.

Many of the stabilising compositions of the invention are soluble or miscible with the perfume normally used in commercial bleaching or detergent compositions. A preferred method of incorporating the stabilising compounds in such cases is to form .a prefume-stabiliser mixture which is then sprayed onto the remainder of the bleaching composition.

A number of scouring powders of the following composition were made up:

Ingredient: Percentage by weight Sodium dodecyl benzene sulphonate (85% AD.) 4.4 Sodium tripolyphospihate 2.0 Sodium carbonate 1.0

Trichlorocyanuric acid 0.56 Stabilisin g compound according to the invention Fine silica As noted in the table. Balance to 100.

The procedure in making up the composition was as follows. The sodium dodecylbenzene sulphonate and the inorganic salts were lightly ground with about 1% of the silica. The triohlorocyanuric acid was mixed with a further small amount of the silica (about and the two mixes were then mixed thoroughly with the bulk of the remaining silica by rolling. The stabilising compound was added last as a mixture with the rest of the silica containing 1 to 6% of the compound.

Samples of about 300 g. each of these compositions were stored in afluminum-fioil wrapped cylindrical cardboard canisters, of the type normally used for the retail sale of domestic scouring powders, under three different conditions of temperature and relative humidity for three months. Table A gives the loss of active chlorine during storage.

Examples 11 and 12 were tested together, in comparison with a control which had no stabiliser added. Example 13 was tested against a control which had no stabiliser added. The control compositions are included for purposes of comparison only, and are not within the scope of the invention claimed.

What is claimed is:

1. A bleaching composition consisting essentially of an effective amount of a bleaching agent selected from the group consisting of trichorocyanuric acid, dichlorocyanuric acid and mixtures thereof stabilized against loss of active chlorine by a stabilizing amount of an ethylenically unsaturated stabilizing agent of the general formula R-CH=CH-X where R is selected from the group consisting of phenyl, methoxyphenyl, dimethoxyphenyl, methoxy-hydroxyphenyl, methylenedioxyphenyl, phenylene, dimethoxybenzyl, methoxy-hydroxybenzyl and methylenedioxybenzyl and X is selected from the group consisting of hydrogen, phenyl, methylene, methyl, hy-droxymethyl, methoxymethyl, acetyloxymethyl and cinnamoyloxymethyl, said stabilizing agent being reactive with hypochlorous acid, not readily polymerizable and having a boiling point between 150 C. and 360 C. at atmospheric pressure.

2. A composition according to claim 1 in which the bleaching agent is trieh-lorocyanuric acid.

3. A composition according to claim 1 in which the amount of said stabilizing agent is from about 1 to about 50% by weight of the bleaching agent.

4. A composition according to claim 1 in which the amount of the stabilizing agent is from about 2 to about 20% by Weight of the bleaching agent.

TABLE A Percent loss of active chlorine during storage at- E G d PAmountf o 0 l9 7 X. ompoun ercent o 20 0 a 28 C./707 37 C. 70

total eom R.H., months R.H., mont hs R.H., n iorzhs position) Control 1 26 0 79 90 81 95 97 1 Cinnamyl alcohol 0- 01 2 22 40 28 58 67 80 O. 06 3 3 4 6 6 8 90 2 Anethole 0.01 0 24 20 14 50 O. 05 1 O 0 0 0 0 3 Safrole 0. 005 12 23 3 40 70 81 0.02 0 8 1 2 37 52 4 Iso-Salrole 0. 005 18 30 45 41 67 79 0. 02 3 U 7 4 41 6O 5 Engenol 0.01 11 36 71 0. 05 O O O 8 10 12 0 0 92 6 Methyl Eugenol 0- 01 ll 45 71 0. 05 O 0 0 0 9 6 0 13 62 7 Iso-Eugenol 0v 05 0 3 0 1 4 5 4 32 29 8 Methyl iso-Eugenol 0. 05 0 0 0 0 0 4 3 90 97 9 Stilbene 0- 01 0 7 3 0 2O 62 40 88 96 0. 05 1 l 2 0 2 6 7 33 84 10 Indene 0.01 0 6 17 45 81 94 0. ()5 0 0 0 O 67 84 1 The Control composition is included for invention claimed.

Examples 11-13 p p 0f mparison only and is not within the scope of the 5. A composition according to claim 1 in which the Scouri-ng powder compositions were made in the man- 60 stablhzmg agent 13 eugenolner described for Examples 1-10.

Samples of about 10 gm. of each or these compositions were stored in sealed glass tubes at 50 C. Table B gives the losses of active chlorine during the storage periods.

6. A composition according to claim 1 in which the stabilizing agent is i-soeugenol.

7. A composition according to claim 1 in which the stabilizing agent is safrole.

TABLE B Percent of Percent loss of available Compound Chlorine during storage Example Compound in Total Composition 2 weeks 4 weeks Control Nil 45 71 11 Cinnamyl acetate 0. l 39 53 Cinnamyl methyl ether... 0. 1 31 39 Nil 68 Cinnamyl cinnamate 0.05 21 22 5 6 8. A composition according to claim 1 in which the FOREIGN PATENTS stabilizing agent is isosafrole. 848,397 9/1960 Great Britain References Cited by the Examiner OTHER REFERENCES UNIT STATES PATENTS 5 Organic Chemistry, Szmant, Prentice-Hall, 1957, p. 2,947,792 8/1960 Skeete'rs 252-171 X'R 3,100,804 8/1963 Alramo XR LEON D. ROS'DOL, Primary Examiner. 3,108,078 10/1963 WiXOn 252-95 3,108,079 10/1963 Wix-On 252*97 XR JULIUS GREENWALD Exammer- 3,123,439 3/1964 McMaster et a1. 252-384 XR 10 WE B ATT, Assis ant Examiner.

UNITED STATES 'PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3, 278 ,443 October 11 1966 Samuel Claude Bright et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 59, for "prefume" read perfume column 3, line 18, for "1%" read 10% columns 3 and 4, TABLE A, in the heading to the third column, before "Percent" insert an opening parenthesis; column 3, line 62, for "or" read of column 4, line 10, for "trichorocyanuric" read trichlorocyanuric Signed and sealed this 29th day of August 1967.

( AL) Attest:

ERNEST W. SWIDER EDWARD]. BRENNER Attesting Officer Commissioner of Patents 

1. A BLEACHING COMPOSITION CONSISTING ESSENTIALLY OF AN EFFECTIVE AMOUNT OF BLEACHING AGENT SELECTED FROM THE GROUP CONSISTING OF TRECHLOROCYANURIC ACID, DICHLOROCYANUTIC ACID AND MIXTURES THEREOF STABLIZED AGAINST LOSS OF ACTIVE CHLORINE BY A STABILIZING AMOUNT OF AN ETHYLENICALLY UNSATURATED STABILIZING AGENT OF THE GENERAL FORMULA R-CH=CH-X WHERE R IS SELECTED FROM THE GROUP CONSISTTING SISTING OF PHENYL, METHOXYPHENYL, DIMETHOXYPHENYL, METHOXY-HYDROXYPHENYL, METHYLENEDIOXYPHENYL, PHENYLENE, DIMETHOXYBENZYL, METHOXY-HYDROXYBENZYL AND METHYLENEDIOXYBENZYL AND X IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, PHENYL, METHYLENE, METHYL, HYDROXYMETHYL, METHOXYMETHYL. ACETYLOXYMETHYL AND CINNAMOYLOXYMETHYL, SAID STABILIZING AGENT BEING REACTIVE WITH HYPOCHLOROUS ACID, NOT READILY POLYMERIZABLE AND HAVING A BOILING POINT BETWEEN 150*C. AND 360*C. AT ATMOSPHERE PRESSURE. 